1. Field of the Invention
The present invention relates to the field of gas turbines, and is concerned with an axial compressor.
2. Brief Description of the Related Art
Injection of water into the compressor of a gas turbine has been known for some length of time as a means for increasing the output of the gas turbine plant (see, for example, U.S. Pat. No. 5,867,977 or WO-A1-03/048544). On the other hand, however, it is also true that the aerodynamic efficiency of the compressor stages is not optimum in operation with water injection. This means that mismatching effects with regard to the impingement of the flow onto the blades occur, such effects becoming the more significant, the more water is injected into the compressor. Injection quantities of up to 2% of the mass intake flow of dry air are already being considered at the present time, and in future the injected quantities will perhaps be even greater.
The mismatching of the blades optimized for dry operation to the on flow conditions within the compressor stages, said on flow conditions changing with the injection of water, leads to increased losses in the stages, these losses lowering the efficiency of the plant.